The present invention generally relates to a loading unit for a case housing a recording disk, and more particularly to a loading unit for a case housing a recording disk which is used in a recording and/or reproducing apparatus, such as a magnetic disk apparatus, an optical disk apparatus, and a magneto optic disk apparatus.
A loading unit is used in a magnetic disk apparatus which is a type of recording and/or reproducing apparatus. For example, a 3.5-inch floppy disk is housed in a disk cartridge which is a thin rectangular case. This disk cartridge has an opening covered by a shutter. In a disk drive unit which drives the 3.5-inch floppy disk housed in the disk cartridge, when the disk cartridge is loaded at a predetermined position (referred to as a loaded position) in the disk drive unit, the shutter of the disk cartridge is opened and then magnetic heads are brought via the opening into contact with respective surfaces of the 3.5-inch floppy disk. The magnetic heads comprise an upper head and a lower head. The upper head is mounted at an end of an arm which is supported by a carriage so as to be capable of pivoting on a predetermined axis in an up-down direction, and the lower head is fixed on the carriage. In a case where the disk cartridge is not loaded into the disk drive unit, the upper head and the lower head are separated from each other by a predetermined distance. The disk cartridge is inserted between the upper head and the lower head in such a way that the disk cartridge is not in contact with the lower head. In addition, the upper head is displaced by a pivot operation of the arm to a predetermined position so that the disk cartridge is not in contact with the upper head.
How to make the disk drive unit using the loading unit thin has been examined. That is, it has been examined how to bring the position to which the upper head is displaced close to the disk cartridge and to decrease the distance between the lower head and the disk cartridge under a condition in which the disk cartridge is inserted between the upper head and lower head. However, as there is a possibility that the disk cartridge will hit and damage the upper head or the lower head when it is inserted between them due to dimensional tolerances and deformation of the disk cartridge and other parts, the conventional disk drive unit cannot be made thin.